Add support for invoking AOT to the Maven Plugin

This commit adds an `aot-generate` goal to the Maven Plugin that
triggers AOT generation on the application. The new goal shares a
number of properties with the existing `run` goal and uses the same
algorithm to detect the main class to use.

Closes gh-30525

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/java/org/springframework/boot/maven/AotGenerateTests.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2012-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.maven;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.TestTemplate;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for the Maven plugin's AOT support.
+ *
+ * @author Stephane Nicoll
+ */
+@ExtendWith(MavenBuildExtension.class)
+public class AotGenerateTests {
+
+	@TestTemplate
+	void whenAotRunsSourcesAreGenerated(MavenBuild mavenBuild) {
+		mavenBuild.project("aot").goals("package").execute((project) -> {
+			Path aotDirectory = project.toPath().resolve("target/spring-aot/main");
+			assertThat(collectRelativeFileNames(aotDirectory.resolve("sources")))
+					.containsOnly("org/test/SampleApplication__ApplicationContextInitializer.java");
+			assertThat(collectRelativeFileNames(aotDirectory.resolve("resources"))).containsOnly(
+					"META-INF/native-image/org.springframework.boot.maven.it/aot/reflect-config.json",
+					"META-INF/native-image/org.springframework.boot.maven.it/aot/native-image.properties");
+		});
+	}
+
+	@TestTemplate
+	void whenAotRunsSourcesAreCompiled(MavenBuild mavenBuild) {
+		mavenBuild.project("aot").goals("package").execute((project) -> {
+			Path classesDirectory = project.toPath().resolve("target/classes");
+			assertThat(collectRelativeFileNames(classesDirectory))
+					.contains("org/test/SampleApplication__ApplicationContextInitializer.class");
+		});
+	}
+
+	@TestTemplate
+	void whenAotRunsResourcesAreCopiedToTargetClasses(MavenBuild mavenBuild) {
+		mavenBuild.project("aot").goals("package").execute((project) -> {
+			Path classesDirectory = project.toPath().resolve("target/classes/META-INF/native-image");
+			assertThat(collectRelativeFileNames(classesDirectory)).contains(
+					"org.springframework.boot.maven.it/aot/reflect-config.json",
+					"org.springframework.boot.maven.it/aot/native-image.properties");
+		});
+	}
+
+	Stream<String> collectRelativeFileNames(Path sourceDirectory) {
+		try {
+			return Files.walk(sourceDirectory).filter(Files::isRegularFile)
+					.map((path) -> path.subpath(sourceDirectory.getNameCount(), path.getNameCount()).toString());
+		}
+		catch (IOException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
+
+}

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/aot/pom.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<groupId>org.springframework.boot.maven.it</groupId>
+	<artifactId>aot</artifactId>
+	<version>0.0.1.BUILD-SNAPSHOT</version>
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>@java.version@</maven.compiler.source>
+		<maven.compiler.target>@java.version@</maven.compiler.target>
+	</properties>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>@project.groupId@</groupId>
+				<artifactId>@project.artifactId@</artifactId>
+				<version>@project.version@</version>
+				<executions>
+					<execution>
+						<goals>
+							<goal>aot-generate</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot</artifactId>
+			<version>@project.version@</version>
+		</dependency>
+		<dependency>
+			<groupId>jakarta.servlet</groupId>
+			<artifactId>jakarta.servlet-api</artifactId>
+			<version>@jakarta-servlet.version@</version>
+			<scope>provided</scope>
+		</dependency>
+	</dependencies>
+</project>

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/src/intTest/projects/aot/src/main/java/org/test/SampleApplication.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.test;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration(proxyBeanMethods = false)
+public class SampleApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(SampleApplication.class, args);
+	}
+
+}